backend3.py

import gradio as gr
import tempfile
import os
import json
from io import BytesIO
from collections import deque
from dotenv import load_dotenv
from langchain_openai import ChatOpenAI
from langchain.schema import HumanMessage, SystemMessage
from langchain.chains import LLMChain
from langchain.prompts import PromptTemplate
from openai import OpenAI
import time

# Imports - Keep only what's actually used.  I've organized them.
from generatorgr import (
    generate_and_save_questions as generate_questions_manager,
    update_max_questions,
)
from generator import (
    PROFESSIONS_FILE,
    TYPES_FILE,
    OUTPUT_FILE,
    load_json_data,
    generate_questions,  # Keep if needed, but ensure it exists
)
from splitgpt import (
    generate_and_save_questions_from_pdf3,
    generate_questions_from_job_description,
)
# ai_config.py is no longer directly imported, functions are redefined here to handle missing API key.
# from ai_config import convert_text_to_speech # Redundant import, redefined below.
from knowledge_retrieval import get_next_response, get_initial_question
from prompt_instructions import get_interview_initial_message_hr
from settings import language
from utils import save_interview_history
from tools import store_interview_report, read_questions_from_json

load_dotenv()  # Load .env variables

class InterviewState:
    """Manages the state of the interview."""

    def __init__(self):
        self.reset()

    def reset(self, voice="alloy"):
        self.question_count = 0
        # Corrected history format: List of [user_msg, bot_msg] pairs.
        self.interview_history = []
        self.selected_interviewer = voice
        self.interview_finished = False
        self.audio_enabled = True
        self.temp_audio_files = []
        self.initial_audio_path = None
        self.interview_chain = None
        self.report_chain = None
        self.current_questions = []
        self.history_limit = 5  # Limit the history (good for performance)

    def get_voice_setting(self):
        return self.selected_interviewer

interview_state = InterviewState()

def initialize_chains():
    """Initializes the LangChain LLM chains."""
    openai_api_key = os.getenv("OPENAI_API_KEY")
    if not openai_api_key:
        print("OpenAI API key not found. Chains will not be initialized.")
        interview_state.interview_chain = None  # Set to None to indicate not initialized
        interview_state.report_chain = None
        return False # Indicate chains were not initialized
    try:
        llm = ChatOpenAI(
            openai_api_key=openai_api_key, model="gpt-4o", temperature=0.7, max_tokens=750
        )
        interview_prompt_template = """
        You are Sarah, an empathetic HR interviewer conducting a technical interview in {language}.
        Current Question: {current_question}
        Previous conversation history:
        {history}
        User's response to current question: {user_input}
        Your response:
        """
        interview_prompt = PromptTemplate(
            input_variables=["language", "current_question", "history", "user_input"],
            template=interview_prompt_template,
        )
        interview_state.interview_chain = LLMChain(prompt=interview_prompt, llm=llm)

        report_prompt_template = """
        You are an HR assistant tasked with generating a concise report based on the following interview transcript in {language}:
        {interview_transcript}
        Summarize the candidate's performance, highlighting strengths and areas for improvement. Keep it to 3-5 sentences.
        Report:
        """
        report_prompt = PromptTemplate(
            input_variables=["language", "interview_transcript"], template=report_prompt_template
        )
        interview_state.report_chain = LLMChain(prompt=report_prompt, llm=llm)
        return True # Indicate chains were initialized
    except Exception as e:
        print(f"Error initializing chains: {e}")
        interview_state.interview_chain = None
        interview_state.report_chain = None
        return False # Indicate chains were not initialized


def generate_report(report_chain, history, language):
    """Generates a concise interview report."""
    if report_chain is None:
        return "Report generation is unavailable because the API key is not set." # Handle uninitialized chain
    # Convert the Gradio-style history to a plain text transcript.
    transcript = ""
    for user_msg, bot_msg in history:
        transcript += f"User: {user_msg}\nAssistant: {bot_msg}\n"
    report = report_chain.invoke({"language": language, "interview_transcript": transcript})
    return report["text"]

def reset_interview_action(voice):
    """Resets the interview state and prepares the initial message."""
    interview_state.reset(voice)
    if not initialize_chains(): # Initialize chains and check if successful
        initial_message_text = "OpenAI API key is not configured. Please set it in the Admin Panel to start the interview with full functionality."
        initial_audio_path = convert_text_to_speech_updated(initial_message_text) # Still try TTS for error message
        return (
            [[None, initial_message_text]],  # [user_msg, bot_msg]. User starts with None.
            gr.Audio(value=initial_audio_path, autoplay=True) if initial_audio_path else None, # Audio output might be None
            gr.Textbox(interactive=False),  # Disable textbox if API key is missing, or keep interactive? Let's keep disabled for now.
        )

    print(f"[DEBUG] Interview reset. Voice: {voice}")
    initial_message_text = get_interview_initial_message_hr(5)  # Get initial message
    # Convert to speech and save to a temporary file.
    initial_audio_path = convert_text_to_speech_updated(initial_message_text, voice)

    # Return values in the correct format for Gradio.
    return (
        [[None, initial_message_text]],  # [user_msg, bot_msg].  User starts with None.
        gr.Audio(value=initial_audio_path, autoplay=True) if initial_audio_path else None, # Audio output might be None
        gr.Textbox(interactive=True),  # Enable the textbox
    )

def start_interview():
    """Starts the interview (used by the Gradio button)."""
    return reset_interview_action(interview_state.selected_interviewer)

def construct_history_string(history):
    """Constructs a history string for the LangChain prompt."""
    history_str = ""
    for user_msg, bot_msg in history:
        history_str += f"User: {user_msg}\nAssistant: {bot_msg}\n"
    return history_str

def bot_response(chatbot, user_message_text):
    """Handles the bot's response logic."""
    voice = interview_state.get_voice_setting()
    history_str = construct_history_string(chatbot)

    if interview_state.interview_chain is None: # Check if chain is initialized
        chatbot.append([user_message_text, "Please set up the OpenAI API key in the Admin Panel to continue the interview."])
        return chatbot, None, gr.File(visible=False) # No audio or report if chain is not initialized

    if interview_state.question_count < len(interview_state.current_questions):
        current_question = interview_state.current_questions[interview_state.question_count]
        response_obj = interview_state.interview_chain.invoke(
            {
                "language": language,
                "current_question": current_question,
                "history": history_str,
                "user_input": user_message_text,
            }
        )
        response = response_obj["text"]
        interview_state.question_count += 1
        # Text-to-speech
        temp_audio_path = convert_text_to_speech_updated(response, voice)

        # Update chatbot history in the correct format.
        chatbot.append([user_message_text, response])  # Add user and bot messages
        return chatbot, gr.Audio(value=temp_audio_path, autoplay=True) if temp_audio_path else None, gr.File(visible=False)

    else:  # Interview finished
        interview_state.interview_finished = True
        conclusion_message = "Thank you for your time. The interview is complete. Please review your report."
        # Text-to-speech for conclusion
        temp_conclusion_audio_path = convert_text_to_speech_updated(conclusion_message, voice)

        # Update chatbot history.
        chatbot.append([user_message_text, conclusion_message])
        # Generate and save report.
        report_content = generate_report(
            interview_state.report_chain, chatbot, language
        )  # Pass Gradio history
        txt_path = save_interview_history(
            [f"User: {user}\nAssistant: {bot}" for user, bot in chatbot], language
        )  # Create plain text history
        report_file_path = store_interview_report(report_content)
        print(f"[DEBUG] Interview report saved at: {report_file_path}")
        return (
            chatbot,
            gr.Audio(value=temp_conclusion_audio_path, autoplay=True) if temp_conclusion_audio_path else None,
            gr.File(visible=True, value=txt_path),
        )

def convert_text_to_speech_updated(text, voice="alloy"):
    """Converts text to speech and returns the file path, handles missing API key."""
    api_key = os.getenv("OPENAI_API_KEY")
    if not api_key:
        print("API key is missing, text-to-speech disabled.")
        return None # Return None when API key is missing

    try:
        client = OpenAI(api_key=api_key)
        response = client.audio.speech.create(model="tts-1", voice=voice, input=text)
        with tempfile.NamedTemporaryFile(delete=False, suffix=".mp3") as tmp_file:
            for chunk in response.iter_bytes():
                tmp_file.write(chunk)
            temp_audio_path = tmp_file.name
        return temp_audio_path
    except Exception as e:
        print(f"Error in text-to-speech: {e}")
        return None

def transcribe_audio(audio_file_path):
    """Transcribes audio to text, handles missing API key."""
    api_key = os.getenv("OPENAI_API_KEY")
    if not api_key:
        print("API key is missing, audio transcription disabled.")
        return "" # Return empty string, transcription is unavailable

    try:
        client = OpenAI(api_key=api_key)
        with open(audio_file_path, "rb") as audio_file:
            transcription = client.audio.transcriptions.create(
                model="whisper-1", file=audio_file
            )
        return transcription.text
    except Exception as e:
        print(f"Error in transcription: {e}")
        return ""

def conduct_interview_updated(questions, language="English", history_limit=5):
    """Conducts the interview (LangChain/OpenAI), handles missing API key."""
    openai_api_key = os.getenv("OPENAI_API_KEY")
    if not openai_api_key:
        # Return a placeholder interview step if API key is missing
        initial_message = "⚠️ OpenAI API Key not configured. Please enter your API key in the Admin Panel to start the interview with full functionality. Text responses will be displayed, but advanced features are disabled."
        placeholder_audio_path = convert_text_to_speech_updated(initial_message)

        def placeholder_interview_step(user_input, audio_input, history):
            history.append([None, initial_message]) # bot message in history
            return history, "", placeholder_audio_path, gr.Textbox(interactive=False) # Textbox disabled

        return placeholder_interview_step, initial_message, "API key missing" # Return placeholder and flag

    chat = ChatOpenAI(
        openai_api_key=openai_api_key, model="gpt-4o", temperature=0.7, max_tokens=750
    )
    conversation_history = deque(maxlen=history_limit)  # For LangChain, not Gradio
    system_prompt = (
        f"You are Sarah, an empathetic HR interviewer conducting a technical interview in {language}. "
        "Respond to user follow-up questions politely and concisely. Keep responses brief."
    )
    interview_data = []  # Store Q&A for potential later use
    current_question_index = [0]
    is_interview_finished = [False]
    initial_message = (
        "👋 Hi there, I'm Sarah, your friendly AI HR assistant! "
        "I'll guide you through a series of interview questions. "
        "Take your time."
    )
    final_message = "That wraps up our interview. Thank you for your responses!"

    def interview_step(user_input, audio_input, history):
        nonlocal current_question_index, is_interview_finished
        if is_interview_finished[0]:
            return history, "", None, gr.Textbox(interactive=False)  # No further interaction, textbox disabled

        if audio_input:
            user_input = transcribe_audio(audio_input)
            if not user_input:
                history.append(["", "I couldn't understand your audio. Could you please repeat or type?"]) #Empty string "" so the user input is not None
                audio_path = convert_text_to_speech_updated(history[-1][1]) #Access the content
                return history, "", audio_path, gr.Textbox(interactive=True) # Keep textbox interactive

        if user_input.lower() in ["exit", "quit"]:
            history.append(["", "The interview has ended. Thank you."])#Empty string "" so the user input is not None
            is_interview_finished[0] = True
            return history, "", None, gr.Textbox(interactive=False) # Disable textbox after exit

        # Crucial: Add USER INPUT to history *before* getting bot response.
        history.append([user_input, ""])  # Add user input, bot response pending
        question_text = questions[current_question_index[0]]

        # Prepare history for LangChain (not Gradio chatbot format)
        history_content = "\n".join(
            [
                f"Q: {entry['question']}\nA: {entry['answer']}"
                for entry in conversation_history
            ]
        )
        combined_prompt = (
            f"{system_prompt}\n\nPrevious conversation history:\n{history_content}\n\n"
            f"Current question: {question_text}\nUser's input: {user_input}\n\n"
            "Respond warmly."
        )
        messages = [
            SystemMessage(content=system_prompt),
            HumanMessage(content=combined_prompt),
        ]
        response = chat.invoke(messages)
        response_content = response.content.strip()
        audio_path = convert_text_to_speech_updated(response_content)
        conversation_history.append({"question": question_text, "answer": user_input})
        interview_data.append({"question": question_text, "answer": user_input})

        # Update Gradio-compatible history.  Crucial for display.
        history[-1][1] = response_content  # Update the last entry with the bot's response

        interactive_textbox = gr.Textbox(interactive=True) # Keep textbox interactive in most steps

        if current_question_index[0] + 1 < len(questions):
            current_question_index[0] += 1
            next_question = f"Next question: {questions[current_question_index[0]]}"
            next_question_audio_path = convert_text_to_speech_updated(next_question)
            # No need to add the "Next Question:" prompt to the displayed history.
            #  The bot will say it.  Adding it here would cause a double entry.
            return history, "", next_question_audio_path, interactive_textbox
        else:
            final_message_audio = convert_text_to_speech_updated(final_message)
            history.append([None, final_message])  # Final message, no user input.
            is_interview_finished[0] = True
            interactive_textbox = gr.Textbox(interactive=False) # Disable textbox at the end
            return history, "", final_message_audio, interactive_textbox

    return interview_step, initial_message, final_message


def launch_candidate_app_updated():
    """Launches the Gradio app for candidates."""
    QUESTIONS_FILE_PATH = "questions.json"
    try:
        questions = read_questions_from_json(QUESTIONS_FILE_PATH)
        if not questions:
            raise ValueError("No questions found.")
    except (FileNotFoundError, json.JSONDecodeError, ValueError) as e:
        print(f"Error loading questions: {e}")
        with gr.Blocks() as error_app:
            gr.Markdown(f"# Error: {e}")
        return error_app

    interview_func, initial_message, api_status = conduct_interview_updated(questions) # Get API status

    def start_interview_ui():
        """Starts the interview."""
        history = []
        if api_status == "API key missing": # Check API status from conduct_interview_updated
            initial_combined = initial_message # Initial message already indicates API key missing
            textbox_interactive = gr.Textbox(interactive=False) # Disable textbox if API key missing
        else:
            initial_combined = (
                initial_message + " Let's begin! Here's the first question: " + questions[0]
            )
            textbox_interactive = gr.Textbox(interactive=True) # Enable textbox if API key OK

        initial_audio_path = convert_text_to_speech_updated(initial_combined)
        history.append(["", initial_combined])  # Correct format: [user, bot]  Empty string for user.
        return history, "", initial_audio_path, textbox_interactive # Return interactive textbox status


    def clear_interview_ui():
        """Clears the interview and resets."""
        # Recreate the object in order to clear the history of the interview
        nonlocal interview_func, initial_message, api_status # Include api_status to reset properly
        interview_func, initial_message, api_status = conduct_interview_updated(questions) # Re-init, get API status
        textbox_interactive = gr.Textbox(interactive= (api_status != "API key missing")) # Enable if API key is OK after clear, disable if missing.
        return [], "", None, textbox_interactive # Return textbox interactive state


    def interview_step_wrapper(user_response, audio_response, history):
        """Wrapper for the interview step function."""
        history, user_text, audio_path, new_textbox_interactive = interview_func(user_response, audio_response, history)
        return history, "", audio_path, new_textbox_interactive


    def on_enter_submit(history, user_response):
        """Handles submission when Enter is pressed."""
        if not user_response.strip():
            return history, "", None, gr.Textbox(interactive=True)  # Prevent empty submissions
        history, _, audio_path, new_textbox_interactive = interview_step_wrapper(
            user_response, None, history
        )  # No audio on Enter
        return history, "", audio_path, new_textbox_interactive


    with gr.Blocks(title="AI HR Interview Assistant") as candidate_app:
        gr.Markdown(
            "<h1 style='text-align: center;'>👋 Welcome to Your AI HR Interview Assistant</h1>"
        )
        start_btn = gr.Button("Start Interview", variant="primary")
        chatbot = gr.Chatbot(label="Interview Chat", height=650)
        audio_input = gr.Audio(
            sources=["microphone"], type="filepath", label="Record Your Answer"
        )
        user_input = gr.Textbox(
            label="Your Response",
            placeholder="Type your answer here or use the microphone...",
            lines=1,
            interactive=True,  # Textbox interactive status is controlled by functions
        )
        audio_output = gr.Audio(label="Response Audio", autoplay=True)

        with gr.Row():
            submit_btn = gr.Button("Submit", variant="primary")
            clear_btn = gr.Button("Clear Chat")


        start_btn.click(
            start_interview_ui, inputs=[], outputs=[chatbot, user_input, audio_output, user_input] # user_input for textbox interactive status
        )
        audio_input.stop_recording(
            interview_step_wrapper,
            inputs=[user_input, audio_input, chatbot],
            outputs=[chatbot, user_input, audio_output, user_input], # user_input for textbox interactive status
        )
        submit_btn.click(
            interview_step_wrapper,
            inputs=[user_input, audio_input, chatbot],
            outputs=[chatbot, user_input, audio_output, user_input], # user_input for textbox interactive status
        )
        user_input.submit(
            on_enter_submit,
            inputs=[chatbot, user_input],
            outputs=[chatbot, user_input, audio_output, user_input], # user_input for textbox interactive status
        )
        clear_btn.click(
            clear_interview_ui, inputs=[], outputs=[chatbot, user_input, audio_output, user_input] # user_input for textbox interactive status
        )

    return candidate_app

# --- (End of Candidate Interview Implementation) ---

def cleanup():
    """Cleans up temporary audio files."""
    for audio_file in interview_state.temp_audio_files:
        try:
            if os.path.exists(audio_file):
                os.unlink(audio_file)
        except Exception as e:
            print(f"Error deleting file {audio_file}: {e}")